What Is an Endometrial Biopsy?
An endometrial biopsy is a quick and safe procedure that usually happens in your doctor’s office. During the biopsy, your doctor removes a small piece of tissue from the lining of your uterus — the pear-shaped organ in your lower belly that holds a baby during pregnancy. Afterward, a lab technician will examine the tissue under a microscope to check for any abnormal cells. This helps your doctor spot any problems in your uterus, such as signs of cancer.
The procedure takes about 15 minutes and is often done as a follow-up if an ultrasound or a Pap test shows something unusual. In rare cases, an endometrial biopsy can also be done with anesthesia.
Who Gets This Test?
Your doctor may do an endometrial biopsy if your Pap test shows that you have “precancerous” cells in your uterus. They could also suggest one if you have any of these symptoms:
- Heavy or long periods
- Periods that don’t come at the same time every month
- No periods
- Bleeding after menopause
- Bleeding after taking a breast cancer drug called tamoxifen
- A thickened uterine lining
An endometrial biopsy can’t fix or stop any of these symptoms. But it can help your doctor learn what may be wrong.
Endometrial Biopsy Procedure
Most of the time, you can get this test done in your doctor’s office. You won’t need anesthesia, but your doctor may suggest you take an over-the-counter pain reliever 30 minutes before your visit.
The procedure usually takes 10-15 minutes.
You’ll lie on an exam table with your feet resting in stirrups, just like you would for a Pap test. Your doctor will insert a device called a speculum into your vagina. This holds it open during the procedure.
After your cervix is cleaned, your doctor will insert a very thin, flexible tool to gently collect a tissue sample from the lining (endometrium) of your uterus. If your cervix is tightly closed, your doctor may use small instruments to help open your cervix so they can obtain the biopsy. When they do this, they may also place an instrument on your cervix to help hold it in place. You may feel a slight pinch when it’s placed.
This sample will then be sent to a lab so it can be looked at under a microscope and tested for abnormal cells like cancer.
Endometrial Biopsy Risks
While an endometrial biopsy is generally safe, there is a chance of bleeding and infection. In rare cases, the tools used during the procedure might nick the wall of your uterus, but this is very uncommon.
If you think you may be pregnant, make sure to tell your doctor ahead of time. The biopsy could cause you to miscarry. It’s also important to tell your doctor if you have any allergies or sensitivities, especially to medications, iodine, or latex.
What are the signs of infection after an endometrial biopsy?
You should start to feel better within a day or two of your endometrial biopsy. But if you notice any of the following symptoms, you should contact your doctor, as they could be signs of an infection:
- Vaginal discharge with a strong or foul smell
- Fever or flu-like symptoms, including chills
- Cramps or pelvic pain that can’t be controlled with over-the-counter pain medication, or gets worse after two to three days
- Heavy bleeding
Bleeding After Endometrial Biopsy
It’s normal to have some light spotting and cramping for a few hours to a few days after an endometrial biopsy. Make sure to ask your doctor which over-the-counter pain relievers are safe for you to take. Some, like aspirin, could make you bleed more.
Clayton Alfonso, MD, a board-certified obstetrician and gynecologist and an associate professor of obstetrics and gynecology at Duke University’s School of Medicine, says the bleeding usually looks like the light flow you see during the last few days of your menstrual cycle. “It should not be at the point you’d consider heavy,” he says. “If you’re filling up a full-sized pad in less than an hour or in two hours, that’s more than we would expect from a normal biopsy.”
You can use a sanitary pad or a liner to manage any light bleeding.
It’s also best to avoid strenuous activities or heavy lifting for the first few days following your biopsy, or until you feel better. After that, you can get back to your normal routine.
Alfonso adds that taking time for yourself after the procedure is important. “I always ask patients how they manage menstrual cramps when they have their period. Are you someone who likes to soak in a tub? Are you someone who likes to use a heating pad? Are you someone who finds comfort in things like drinking tea, or whatever your coziness is that helps you feel better about the cramping that you’re going to get?” he says. “That’s going to help you during the recovery.”
Any soreness and cramping should go away after 48 hours, and bleeding usually stops within three days. If your bleeding lasts longer, you should call your doctor.
Endometrial Biopsy Results
If your results are normal, that means the tissue sample looks healthy and that your symptoms aren’t being caused by anything serious in the lining of your uterus.
Abnormal results mean that your doctor found changes in the lining of your uterus that could signal a problem. These changes don’t always mean cancer, but they can be linked to many different conditions that affect the uterus.
Your results may also come back inconclusive. This means that it’s unclear whether or not you have cancer cells in your uterus. If that happens, you may need to have a more involved medical procedure called a dilation and curettage (D&C). During a D&C, your doctor will scrape a bigger sample of tissue from the lining of your uterus for testing in a lab.
What Happens if My Endometrial Biopsy Is Abnormal?
You should get the lab results from your endometrial biopsy back in about a week. If your doctor finds any abnormal cells, there are several possible causes, including:
- Polyps or fibroids (small or large growths in your uterus)
- An infection of your uterus, such as endometritis
- Endometrial cancer
- A thyroid problem
- Hormonal imbalances
Your doctor will go over the results with you. Based on what they reveal, they’ll also explain if any treatment is needed.
Endometrial biopsies aren’t perfect. Because they only take a small, random tissue sample, they can sometimes miss precancerous or cancerous growths. If your symptoms don’t go away, make sure to tell your doctor. You may need to have another type of test to get a clearer picture of what’s going on.
What percentage of endometrial biopsies are cancerous?
In the U.S., endometrial cancer is the most common reproductive cancer among people who have periods. Whether you’re at risk depends on a mix of health, lifestyle, and genetic factors.
“The majority of the time when we do a biopsy, the results are not cancerous in nature, but we’re doing our due diligence because we don’t want to miss the scary thing,” Alfonso says. “Usually, the results are minor and typically fixable.”
The chances of being diagnosed with endometrial cancer go up after menopause. Most cases occur after the age of 60, while diagnosis before 45 is rare. Black people also have a higher risk than White people. One large-scale study found that about 9% of postmenopausal people who visited their doctor for vaginal bleeding (which is one of the main symptoms of endometrial cancer in older women) were later diagnosed.
Other things that can affect how likely you are to have endometrial cancer include:
- Obesity
- Starting your period early or going through menopause late
- A family history of endometrial cancer
- Hormonal conditions that affect ovulation, like polycystic ovary syndrome or diabetes
- Taking hormone therapy for breast cancer (though the benefits usually outweigh the risks)
Because endometrial cancer usually shows symptoms — mainly, bleeding — it’s often caught at a stage when it’s easier to treat.
Takeaways
An endometrial biopsy is a quick, safe, and easy procedure that can help doctors understand what’s causing unusual bleeding or other symptoms in your uterus. It’s also a useful way to catch cancer in its early stages. You might have some cramping or spotting afterward, but serious complications are rare. Be sure to follow your doctor’s recovery instructions and make a follow-up appointment if you have ongoing pain, bleeding, or any signs of an infection. If your results come back abnormal or unlear, your doctor may suggest further tests.
Endometrial Biopsy FAQs
Does an endometrial biopsy hurt?
An endometrial biopsy can be uncomfortable and may cause some cramping, but the pain is usually mild and short-lived. Taking an over-the-counter NSAID medication, such as ibuprofen, before and after the procedure can help.
How long do endometrial biopsy results take?
You’ll usually get your test results within a week after the biopsy.
How long should you rest after an endometrial biopsy?
Recovery from an endometrial biopsy usually only takes a day or two, but some doctors may suggest avoiding intense activities for a few days after the procedure.
What is the cost of an endometrial biopsy?
The cost of an endometrial biopsy depends on your insurance coverage, but it can range from roughly $680 to $1,900.
How thick is a cancerous endometrium?
In postmenopausal women, an endometrium that’s 4 mm or less is considered normal. If thicker than that, an endometrial biopsy should be considered.
